150 BULLETIN 14 5, UNITED STATES NATIONAL MUSEUM 



July 12 (H. Dietrich). Bair's Ranch, Redwood Creek, Humboldt 

 County, June 9 (H. S. Barber). 



Type, allotype, and paratypes. — Cat. No. 40996, U.S.N.M. 



Described from a large series of specimens (one type) collected 

 at the type locality on the Western Black Willow (Salix lasiandra 

 Bentham) by H. E. Burke and Eleanor T. Armstrong. 



This species is rather uniform in size, but there is considerable 

 variation in the coloration as stated above. The prosternal lobe i& 

 usually broadly rounded in front, but in a few of the specimens 

 examined it was broadly, arcuately emarginate. The specimens from 

 Biggs have the elytra dark green and the pronotum more bronzy 

 green, and two specimens from Castle Crag, received from Doctor 

 Fenyes, which I have placed under this species, have the pronotum 

 greenish blue and the elytra a beautiful violaceous blue; otherwise 

 there are no differences. 



It is very closely allied to niveiventris Horn, but is more uniform 

 in size, more shining above, and the pubescence forming spots on the 

 sides of the abdomen, these spots in freshly collected specimens are 

 densely covered with a white efflorescence which is easily rubbed off. 

 It is also allied to populi Fisher, but that species is usually larger, 

 the males have the first abdominal segment feebly concave, and the 

 second segment with a broad, deep, smooth depression at the middle, 

 and the larvae live in poplar and cottonwood. 



47. AGRILUS POPULI, new species 



Figure 34 



Agrilus nnelventris Burke (not Horn), Journ. Econ. Ent., vol. 10, 1917, 

 p. 331 (part).— Frost and Weiss, Canad. Ent., vol. 52, 1920, p. 247 

 (part).— Chamberlin, Journ. N. T. Ent. Soc, vol. 32, for 1924 (1925), 

 p. 193; Cat. Bupresiidae, 1926, p. 71 (part). — Essig, Ins. Western 

 North Amer., 1926, p. 403 (part). 



Male. — Form resembling that of niveiventris Horn, strongly shin- 

 ing, and feebly flattened above ; head green, becoming slightly cupre- 

 ous on the occiput; pronotum bronzy green, and sometimes with a 

 brownish cupreous tinge; elytra varying from golden green to red- 

 dish cupreous, and sometimes with a distinct violaceous tinge; 

 beneath bronzy green. 



Head with the front rather narrow, feebly convex, about equal in 

 width at bottom and top, the lateral margins strongly, arcuately 

 expanded at middle, and with a vague longitudinal groove extending 

 from occiput to middle of front ; surface coarsely, confidently punc- 

 tate, more or less rugose, and rather densely clothed with long, 

 recumbent, whitish pubescence; epistoma transverse between the 

 antennae, and broadly, rather deeply, arcuately emarginate in front; 



